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Biomedical subjects

I Wagner

Publications and source records attributed to I Wagner.

At least 19 recordsLinked to original sources
PubMed2005

Hemodynamic performance and incidence of patient-prosthesis mismatch of the complete supraannular perimount magna bioprosthesis in the aortic position.

BACKGROUND: Complete supraannular placement and smaller stent design allow the implantation of a Perimount Magna bioprosthesis with a larger inner diameter than that of a standard Perimount. This study compares the hemodynamic performance and the incidence of patient-prosthesis mismatch (PPM) of both prostheses. METHODS: 128 patients underwent aortic valve replacement, receiving either a Magna (n = 57) or a standard (n = 71) prosthesis. Inner aortic annulus diameter was measured intraoperatively by a hegar dilator to match echocardiographically obtained results to the annulus diameter instead of matching them to labelled valve size. RESULTS: The Magna was significantly superior with respect to mean pressure gradient and effective orifice area in patients with an annulus diameter of 22-23 mm. In patients with an annulus diameter < 22 mm or > 23 mm, there was a non-significant trend towards superior hemodynamics in the Magna group. Severe PPM (effective orifice area index < or = 0.65 cm (2)/m (2)) was present in 11.1% (Magna) vs. 42.1% (Standard) of patients with an annulus diameter < 22 mm; in 0% (Magna) vs. 13.8% (Standard) with an annulus diameter of 22-23 mm; no PPM was seen in patients with annulus diameter > 23 mm in both groups. CONCLUSIONS: The Perimount Magna had a significantly reduced incidence of patient-prosthesis mismatch and superior hemodynamics compared to the standard Perimount.

Age Factors↗
PubMed2003

A qualitative study of Australian GPs' attitudes and practices in the diagnosis and management of attention-deficit/hyperactivity disorder (ADHD).

BACKGROUND: The importance of general practice involvement in the care of attention-deficit/ hyperactivity disorder (ADHD) is increasing due to the rising numbers of patients who present with the disorder. It has been suggested by consensus bodies that GPs should be identifying and referring patients at the severe end of the ADHD spectrum and managing those with less severe symptoms. However, GPs' views of their role in ADHD care are unknown. OBJECTIVE: Our aim was to explore the attitudes and practices of Australian GPs towards the diagnosis and management of ADHD. METHODS: We conducted a series of focus groups to explore GPs' beliefs regarding the causes of ADHD, their perceived role in ADHD diagnosis and management and their views on the role of behaviour therapies and pharmacotherapies in ADHD management. The subjects were 28 GPs in six focus groups. RESULTS: GPs in this study did not want to be the primary providers of care for patients with ADHD. Participants indicated a preference to refer the patient to medical specialists for diagnosis and treatment of ADHD, and expressed low levels of interest in becoming highly involved in ADHD care. Concerns about overdiagnosis and misdiagnosis of the disorder, diagnostic complexity, time constraints, insufficient education and training about the disorder, and concerns regarding misuse and diversion of stimulant medications were the reasons cited for their lack of willingness. CONCLUSIONS: The Australian GPs in this study identify a role for themselves in ADHD care which is largely supportive in nature, and involves close liaison with specialist services.

Adult↗
PubMed2002

Thawing of cryopreserved mobilized peripheral blood--comparison between waterbath and dry warming device.

BACKGROUND: Thawing of cryopreserved mobilized peripheral blood (MPB) is routinely performed for autologous and allogeneic MPB transplantation. Usually thawing is achieved by submerging the cell bag in a waterbath (37 degrees C temperature). We compared the effectiveness of thawing cryopreserved MPB in a waterbath with an electric dry-warming device containing warmed gel pads (Sahara, Transmed). METHODS: Two cryopreserved bags from each of 31 apheresis procedures were thawed in a waterbath and under dry conditions in parallel. Viability (dye exclusion), apoptosis/necrosis (annexin/propidiumiodide staining) and clonogenic potential (CFU-E plus BFU-E, CFU-GM) of the cells were tested after thawing. RESULTS: Statistical analysis by Wilcoxon matched-pair test showed no significant difference between the thawing procedures in terms of the in vitro parameters tested. DISCUSSION: Our results indicate that thawing of cryopreserved MPB using dry warming and water bath give similar viability, apoptosis/necrosis rate and clonogenic potential. Both procedures take about the same amount of time and are easy to perform. Nevertheless, the potentially decreased risk of bacterial contamination of either the cell product or the patient room, and guidelines of good clinical practice (GCP), favor the use of the dry warming procedure.

Cell Survival↗
PubMed2002

Morphometric analyses of endometriotic tissues to determine their grade of activity.

The last revised classification of endometriosis of the American Fertility Society takes the extension of endometriotic lesions and the three macroscopic appearances of this disease into consideration. The aim of this study was to determine whether morphometric analyses are able to describe the grade of activity of endometriotic lesions according to their macroscopic-morphological appearances. Endometriotic samples of 45 patients were analyzed morphometrically using a semiautomatical planimeter. Six different parameters were investigated: the cytoplasmic surface of epithelial cells, the nucleus surface of epithelial cells, the nucleus surface of stromal cells, the gland surface, the gland circumference and the gland diameter. No statistically significant differences (p > 0.05) between the macroscopic appearances of the endometriotic lesions and the six analyzed morphometric parameters were found. The majority of the endometriotic lesions showed median values for the cytoplasmic surface of epithelial cells, the nucleus surface of epithelial cells and the gland surface that did not differ from the median values of all tissues, independently of the macroscopic appearances of these lesions and of the corresponding serum hormonal levels of 17 beta-estradiol and progesterone that were measured at the time of biopsy (p > 0.05). Our morphometric data showed that the red and so-called 'active' endometriotic lesions did not exhibit different morphometric characteristics from the so-called 'inactive' black or white lesions. We found that white and black lesions showed in some cases higher morphometric values than the mean values, so that these macroscopic appearances of endometriotic lesions cannot be considered as 'burned-out' endometriotic tissues. Therefore, black or white endometriotic lesions also have to be considered as therapeutically relevant, as they cannot be defined as 'inactive' endometriosis.

Adult↗
PubMed2001

[Laryngeal immobility after thyroidectomy].

One of the most common complications of surgery of the thyroid gland is vocal folds immobility. New advances in its management have been achieved over the last few years. Laryngeal electromyography, stroboscopy, and computerized analysis of the voice help guide diagnosis, allowing differentiation between recurrent nerve paralysis and glottis traumatism due to intubation, and further follow-up of recovery with relevant therapeutic decisions. In case of unilateral vocal fold paralysis, intrafold silicone or injection of autologous fat is more and more routinely used to obtain vocal rehabilitation. In case of bilateral vocal fold paralysis, to avoid tracheotomy, partial posterior cordectomy using laser surgery restores sufficient laryngeal airflow, with minimal vocal sequelae. Early management of these complications by teams of specialists should allow appropriate and less invasive surgery.

Aged↗
PubMed2001

Application of laser measuring, numerical simulation and rapid prototyping to titanium dental castings.

OBJECTIVES: This paper describes a method of making titanium dental crowns by means of integrating laser measuring, numerical simulation and rapid prototype (RP) manufacture of wax patterns for the investment casting process. METHODS: Four real tooth crowns (FDI No. 24, 25, 26, 27) were measured by means of 3D laser scanning. The laser digitized geometry of the crowns was processed and converted into standard CAD models in STL format, which is used by RP systems and numerical simulation software. Commercial software (MAGMASOFT) was used to simulate the casting process and optimize the runner and gating system (sprue) design. RP crowns were 'printed' directly on a ModelMaker II 3D Plotting System. A silicone negative mold (soft tool) was made from the RP crowns, then more than hundreds wax crowns were duplicated. The duplicated crowns were joined to the optimized runner and gating system. By using the investment casting process 20-25 replicas of each crown were made on a centrifugal casting machine. All castings were examined for porosity by X-ray radiographs. RESULTS: By using the integrated scanning, simulation, RP pattern and casting procedure, cast crowns, free of porosity, with excellent functional contour and a smooth surface finish, were obtained from the first casting trial. SIGNIFICANCE: The coupling of laser digitizing and RP indicates a potential to replace the traditional 'impression taking and waxing' procedure in dental laboratory, with the quality of the cast titanium prostheses also being improved by using the numerically optimized runner and gating system design.

Calcium Sulfate↗
PubMed2001

Numerical simulation of the casting process of titanium tooth crowns and bridges.

The objectives of this paper were to simulate the casting process of titanium tooth crowns and bridges; to predict and control porosity defect. A casting simulation software, MAGMASOFT, was used. The geometry of the crowns with fine details of the occlusal surface were digitized by means of laser measuring technique, then converted and read in the simulation software. Both mold filling and solidification were simulated, the shrinkage porosity was predicted by a "feeding criterion", and the gas pore sensitivity was studied based on the mold filling and solidification simulations. Two types of dental prostheses (a single-crown casting and a three-unit-bridge) with various sprue designs were numerically "poured", and only one optimal design for each prosthesis was recommended for real casting trial. With the numerically optimized design, real titanium dental prostheses (five replicas for each) were made on a centrifugal casting machine. All the castings endured radiographic examination, and no porosity was detected in the cast prostheses. It indicates that the numerical simulation is an efficient tool for dental casting design and porosity control.

Journal Article↗
PubMed2001

[Inverted papilloma: endoscopic versus external surgery. Apropos of 28 cases].

To evaluate the role of endoscopic versus external surgery in the treatment of inverted papillomas, the clinical courses of 35 patients over a period of 10 years were reviewed. 13 patients were treated endoscopically whereas 15 were treated with an external approach. 7 patients with a post operative follow up of less than 12 months were excluded from the study. Recurrences occurred in 4 patients, 2 patients had been treated by endoscopic surgery and 2 by medial maxillectomy by lateral rhinotomy. 3 patients were diagnosed with squamous cell carcinoma. Salvage surgery was performed by an external procedure or endoscopically depending on the extension of the recurrence. Late complications occurred in both groups: cosmetic complaints and epiphora were more frequently encountered after external treatment. Functional complaints were noted after endoscopic treatment. If there is no evidence of associated malignancy, if complete exposure of the tumor is possible and long term follow up is feasible, the authors propose endoscopic surgery as first line treatment to excise the body of the tumor, assess it's extension, and remove the root of the tumor. If this is not the case, medial maxillectomy by external approach should be performed.

Adolescent↗
PubMed2001

[Cranialization of the frontal sinus].

UNLABELLED: In the surgery of frontal sinus exclusion, the place of cranialization is still controversial. Our aims were to describe the operative technique, report our results and discuss its indications. PATIENTS AND METHODS: Nineteen patients were operated according to this technique between 1984 and 1997. Cranialization was performed in the first place for tumors, osteitis, traumatisms and benign tumors or mucoceles with a special location. In patients with chronic sinusitis or mucocele, it was performed in the second place when functional surgery was considered as failure and because sinus obliteration seemed to be inappropriate. RESULTS: There was no mortality nor anosmia linked to the procedure. Postoperative sequelae were related to the disease or to the surgical approach. After a median follow-up of 29 months, no disease recurrence was observed. CONCLUSION: Cranialization of frontal sinus gives good results in selected patients, with low morbidity. Even though its indications are infrequent, this technique has its place in the surgical exclusion of frontal sinus.

Adolescent↗
PubMed2000

Use of the carbon dioxide laser for tracheobronchial pathology in children.

The carbon dioxide (CO2) laser has been used to treat tracheobronchial pathology for more than 20 years. It was initially employed in adults and now has been found to be useful in the treatment of certain lesions in children. We present our experience with this technique in 30 patients treated with a CO2 bronchoscopic laser from 1987 to 1995 in the Ear, Nose, and Throat Department of Armand Trousseau Hospital. Four different types of pathologies have been successfully treated with the laser: selective cases of tracheobronchial stenosis following trauma and/or secondary to neonatal ventilation, posttraumatic tracheobronchial granuloma (due to foreign bodies or tracheotomies), tracheobronchial granulomas of infectious origin (tuberculosis), and selective cases of tracheobronchial tumor.

Adolescent↗
PubMed2000

[Surgical treatment of severe sleep apnea syndrome by maxillomandibular advancing or mental tranposition].

Surgery of the facial skeleton or the tongue may be envisaged in case of failure of continuous positive pressure ventilation for severe sleep apnea syndrome defined by a apnea-hyponea index greater than 30/h. We present here our results in patients treated by maxillo-mandibular advancing and mental transposition. We define the surgical indications. Between January 1993 and June 1997, 41 patients, mean age 49 years, with severe sleep apnea syndrome (mean apnea-hyponea index =58.5/h) were treated by maxillo-mandibular advancing (21 cases) or mental transposition (20 cases) depending on the cephalometric work-up including lateral teleradiography and sagittal magnetic resonance imaging of the tongue. Functional outcome was good in both groups. Objective success (postoperative apnea-hyponea index <20) was 70.5 % after bimaxillary advancing (mean apnea-hypopnea index =17), but only 25 % after mental transposition (mean apnea-hyponea index =44.5). Maxillomandibular advancing is a major procedure which can be effective in sleep apnea patients with severe craniofacial skeletal anomalies. Its applications in apneic patients with no skeletal anomaly remains a subject of debate. Conversely, there would appear to be very few indications for mental transposition.

Adult↗
PubMed2000

[Retrospective cephalometric analysis for surgically treated obstructive sleep apnea: therapeutic deductions].

PURPOSE OF THE STUDY: The goal of surgical treatment for severe sleep apnea syndrome is to alleviate the upper airway obstruction. The narrowing site must be precisely determined during the preoperative evaluation to ensure success. We suggest that cephalometric analysis using a lateral cephalic radiograph to evaluate bony structures combined with magnetic resonance imaging (MRI) to study soft tissues may achieve this goal. The purpose of this study was to determine the role of two different cephalometric analysis systems for determining surgical strategy and to underline factors predictive of success for different surgical procedures. MATERIALS AND METHOD: We prospectively studied 73 sleep apnea patients. The preoperative evaluation included MRI and two different cephalometric analyses on a lateral cephalic radiograph: Tweed's and Delaire's analyses. Three surgical techniques were performed: mandibular osteotomy and geni tubercule advancement, maxillo-mandibular advancement and tongue base reduction with hypoepiglottoplasty via a cervical approach. RESULTS: Tweed's analysis appeared to underestimate maxillo-mandibular deficiencies compared with Delaire's analysis; the later seemed to be more sensitive. MRI did not prove to be useful in predicting surgical outcome. MRI was non-contributive in our preoperative evaluation. DISCUSSION: We suggest a new surgical strategy using two procedures: maxillo-mandibular advancement and tongue base reduction. Indications are based on the results of two cephalometric analyses (Tweed and Delaire) and the measurement of the oropharyngeal surface.

Adult↗
PubMed2000

[Treatment of snoring with controlled temperature radiofrequency: short- and mid-term tolerance and efficacy].

UNLABELLED: Uvulopalatopharyngoplasty and laser pharyngotomy can provide effective and definitive cure of snoring. These methods are however very painful. The ideal treatment would be not only effective but also pain free. MATERIAL AND METHODS: We assessed prospectively the efficacy and tolerance to temperature controlled radiofrequency (somnoplasty). This technique was applied to the velar palate in 15 snoring patients. Self assessment was used to evaluate outcome. The patients daily recorded: uneasiness, pain, drug use, and food intake. Their spouse scored snoring for 6 to 8 weeks after the end of treatment and more than 6 months after the last treatment session. RESULTS: We achieved 80% success after 2.1 sessions. Pain was minimal. A sensation of uneasiness was frequent and led to minimal drug use. After a mean 13 months, half of the patients experienced a recurrence or an aggravation of their snoring level. Overall satisfaction rate was 69%. CONCLUSION: These preliminary results suggest that radiofrequency is well tolerated and effective in the short- and mid-term for the treatment of snoring.

Adult↗
PubMed1999

Inter-organellar crosstalk in higher plants: impaired chloroplast development affects mitochondrial gene and transcript levels.

Co-ordination of gene expression between the three genomes present in plastids, mitochondria and nucleus is of crucial importance for plant cells. Previous studies revealed that in white leaves of the albostrians (Hordeum vulgare cv. Haisa) mutant, photosynthesis-related plastid and nuclear genes are expressed only at an extremely low level. The plastids of this mutant lack ribosomes, photosynthetic activity and have only rudimentary membrane systems. Here we report on the expression of mitochondrial genes in albostrians barley. Steady-state RNA levels of the mitochondrial genes encoding cytochrome oxidase or ATPase subunits, coxII, coxIII, atpA, atp6, atp9 and cob, were observed to be consistently elevated in the white leaves but not in roots. Investigation of mitochondrial DNA revealed an about three-fold enhanced mitochondrial gene copy number in white compared to green leaf cells, but no differential amplification of mitochondrial genes. Analysis of plants in which the white albostrians plastids were combined with a new nuclear background showed that the enhanced transcript levels were a consequence of the impaired plastids and not of the nuclear albostrians allele. Furthermore, plants bleached by the carotenoid biosynthesis inhibitor norflurazon also showed an enhanced mitochondrial transcript level. These findings allow the conclusion that lack of chloroplast activity in an otherwise fully differentiated leaf leads to an increase in mitochondrial gene copy number and an elevated level of mitochondrial transcripts. Our results indicate an influence of plastids on the genetic apparatus of mitochondria in leaves but not in roots.

Chloroplasts↗
PubMed1999

Tongue base reduction with hyoepiglottoplasty: a treatment for severe obstructive sleep apnea.

OBJECTIVE: To describe a surgical procedure for the treatment of severe obstructive sleep apnea syndrome (OSAS), the procedure's indications, and its results. STUDY DESIGN: A retrospective study of 10 male patients with OSAS treated by tongue base reduction with hyoepiglottoplasty (TBRHE) at the Foch Hospital (Suresnes, France) between 1994 and 1997. Patients had a mean body mass index (BMI) of 32 kg/m2, a mean respiratory disturbance index (RDI) of 70 events/h, and a mean minimal oxygen saturation of 78%. They had refused positive airway pressure therapy or wished to discontinue it. METHODS: Subtotal tongue base reduction preceded by lingual neurovascular bundle identification and derouting, epiglottal verticalization, mouth floor horizontalization, and hyoid bone repositioning was performed, associated in some cases to uvulopalatopharyngoplasty (UPPP). Indications were based on a site-related obstruction, on the absence of craniofacial deficiencies, and on the presence of hyolingual abnormalities determined by cephalometry and magnetic resonance imaging. RESULTS: TBRHE associated to UPPP in most cases had an 80% success rate, based on a postoperative RDI below 20 events/h and a reduction of the preoperative RDI of more than 50%. Snoring and excessive daytime sleepiness decreased or disappeared, respectively, in 100% and 90% of the cases. No neurovascular complications occurred. CONCLUSION: TBRHE is a safe procedure for the neurovascular bundle. Associated to a pharyngotomy, it is an effective treatment for severe OSAS attributable to tongue base obstruction. These results require confirmation in a larger series of patients.

Adult↗
PubMed1999

[Hypoglossal nerve in its intralingual trajectory: anatomy and clinical implications].

There is little literature on the intralingual trajectory of the hypoglosal nerve. We performed an anatomical dissection on 6 cadavers and completed our study with histological examinations. The 12th cranial nerve enters the lower part of the tongue laterally, reaching the anterior border of the hypoglossal muscle where it follows the ascending lingual artery medially to terminate anteriorly to the lingual V. Its terminal branches spread out horizontally in each half of the tongue. There is a paramedial branch, found in all cases, which projects downwardly, posteriorly and medially at the basilingual portion of the genioglossal muscle. These anatomic findings indicate that basiglossectomy removing the entire base of the tongue can be performed without functional sequelae. A certain degree of somatotopy is also found with specific fibers reaching the protractor and retractor muscles. This nerve distribution supports attempts at selective electrical stimulation of the hypoglossal nerve with the aim of dilating the upper airways in patients with sleep apnea syndrome.

Aged↗
PubMed1998

[Tongue base reduction with hyoid-epiglottoplasty. A surgical alternative in severe sleep apnea syndromes].

We present preliminary results and indications of tongue base reduction with hyo-epiglottoplasty for the treatment of severe obstructive sleep apnea syndrome (OSAS) due to isolated hyolingual abnormalities. The procedure consists in a subtotal resection of the tongue base after identification and derouting of the lingual neurovascular bundle. Hypopharyngeal enlargement, epiglottis verticalization, floor of the mouth tension and hyoid bone repositioning are also performed during the procedure. 14 severe OSAS male patients (mean apnea-hypopnea index of 71) were treated in our institution from November 1992 to February 1996. Indications were determined after a cephalometric analysis and a magnetic resonance imaging evaluation. Results were evaluated on clinical and polysomnographic criteria. No neurovascular complications occurred. Clinical results were excellent but success rate based on polysomnography was 50%. These preliminary results led us to change some of the steps in the technique. We also identified a predictive factor of success on the cephalometrics: an oropharyngeal area greater than 25 cm2.

Adult↗